1. Field of the Invention
The present invention is in the field of baby strollers, and particularly relates to a three-wheeled baby stroller that can be folded to a more compact configuration for storage or transportation. The suspension system and the structure of the frame are believed to be novel.
2. The Prior Art
A search of the patent literature revealed that a number of inventors have designed collapsible baby strollers, and some of the most noteworthy designs will now be briefly discussed.
In U.S. Pat. No. 5,536,033 issued Jul. 16, 1996 to Hinkston, there is described a three-wheeled jogging stroller with demountable wheels. The center of gravity of the cargo is located approximately vertically above the rear axle and is supported above the axle by vertically-extending struts. The front and rear axles are connected by rigid frame members.
In U.S. Pat. No. 5,364,119 issued Nov. 15, 1994, Leu describes a stroller that differs from that of Hinkston notably in the addition of a compression spring in each of the vertically-extending struts.
In U.S. Pat. No. 5,299,825 issued Apr. 5, 1994 to Smith there is described a collapsible stroller in which rear stub axles are eccentrically mounted to the frame, and a spring that extends into the space between the front and rear wheels opposes eccentric motion of the rear axles. A similar suspension system is shown in British Patent No. 592,772 issued Sep. 29, 1947 to Hudlass.
In U.S. Pat. No. 5,188,389 issued Feb. 23, 1993, Baechler et al. describe a foldable baby stroller in which the front and rear axles are connected by rigid structural members and in which upright support tubes are pivotally connected to the upper frame. There are no resilient members in the suspension system. This stroller is substantially similar to that shown in U.S. Pat. No. Des. 370,194 issued May 28, 1996 to Baechler et al.
In U.S. Pat. No. 3,653,681 issued Apr. 4, 1972 to Virtue there is shown a baby stroller in which the wheels are mounted at the lower ends of pivoted inclined cross-arms and the upper ends of the cross-arms are connected by a horizontal resilient element.
In U.S. Pat. No. 3,012,796 issued Dec. 12, 1961, Mieding shows a bicycle trailer having two front wheels and one rear wheel. The front axle is mounted on the lower ends of swing arms that are pivotally mounted to the sides of the trailer. Horizontal springs extend rearwardly from the front axle through the space between the front and rear wheels to brackets that are affixed to the bottom of the trailer.
In U.S. Pat. No. 2,492,676, Zajicek shows a collapsible hamper cart in which a spring connects the front and rear axles.
As will be described more fully below, the stroller of the present invention differs significantly from the strollers of the above patents in its suspension system, its structure, and its manner of folding up.